How to Build Snow Shelters

Building snow shelters is an important winter skill which can be used in emergency situations in the backcountry. Snow is a great insulator and works by preventing warm trapped in its crystalline structure from escaping. But more importantly perhaps, is that snow and snow structures provide a very effective barrier against wind chill, which greatly accelerates bodily cooling in winter.

Excellent Snow Shelter Reference

If you want to learn how to build a wide variety of snow shelters, I recommend you get How to Build an Igloo: And Other Snow Shelters. This book is full of cartoon style illustrations that show you how to build a variety of shelters including igloos, slab shelters, snow trenches, shelters built out of spruce traps, drift caves, wind breaks and quinzees. It contains very useful information about the structural and insulating properties of snow, the best tools for building snow shelters, safety considerations, and history.

Shelter Building Practice

We have a lot of snow at my house and I’ve built several of the shelters illustrated in How to Build an Igloo in my front yard, with varying degrees of success. I’d planned on practicing these in New Hampshire this winter, but there’s no need to drive 2-3 hours to the mountains, when we have all of this snow here in Boston!

Building a Quinzee

I’m still digging a quinzee, pictured above. The first step in quinzee construction is to pile up a lot of snow in a mound and let it harden up under the pressure of it’s own weight. After that, you carve out a cavern inside of it and poke an air hole through the top. They take a lot of work to build and you need at least two people to dig them out. I wouldn’t recommend building one unless you have most of a full day to work on it.

Building one by myself has been slow going, but instructive. I started digging mine out using a snow claw, which is a plastic disk that you can use as a substitute for carry an full avalanche shovel on overnights. This proved to be very tiring, especially on my wrists, which bear the weight of the snow when I remove it from the inside of the mound.

Digging out a quinzee requires a shovel, but snow claw is still very useful for carving the curved inner walls and making sure they’re smooth. It is also very good for increasing interior space because you can carve very close to the outer surface of the quinzee’s walls.

Cutting Snow Blocks

Snow blocks facilitate the construction of igloos, a-frame style slab shelters, wind breaks, and covered snow trenches. Snow blocks are used mainly for building higher cost shelters and require multiple people and sufficient time to build. The best kind of snow for snow blocks is cold, dense snow that has been wind packed by continuous wind action and is found in fields or mountain location above treeline.

I tried to carve snow blocks out a sheet cake (raised platform) of stomped down snow at my house, but it didn’t work, and they felt apart too easily.

Alternatively, it is possible to cut crust blocks: when the surface of the snowpack thaws and refreezes, a hard crust or icy glaze forms on it’s surface. Beneath this hardened surface, there is layer of ice crystals, several inches thick, attached to the hardened crust. Blocks can be cut from the surface as is, or the surface can be stomped down, and then cut using a shovel, to form thinner blocks that can also be used for construction purposes.

Snow Trench with Flat Tarp on Top

Expedient Snow Shelters

The are several types of expedient snow shelters including tarp covered snow trenches, trenches under pyramid tarps, and mounded walls. These are the types of shelters I envision myself using in the mountains because they are quick to build and provide sufficient shelter from the wind and elements, when used in combination with a bivy bag.

To practice these, I started by building a rectangular snow trench about 3 feet deep, 3 feet wide, and 8 feet long. Although, you can use a snow trench alone with a bivy bag as a wind break, I decided to try some variations with a flat 9 oz silnylon tarp.

The first variant I tried uses hiking poles and/or skis to span the trench. I laid my tarp on top and then tried to anchor the sides with snow to keep the wind from blowing the tarp off. This didn’t work very well for a few reasons:

I’d dug my trench too wide, and fully opened, the poles barely extended across the top opening. On hindsight, it’s better to have a narrower trench at the top and to dig sideways at the bottom to expand the space, using the overhands for protection.

In addition, my trench was too long and was open at one end, allowing the wind to billow the tarp. It would have been better to dig a trench with no end opening, and perhaps a bit shorter. Having a small opening in the tarp, at one end, however is useful to limit internal condensation and provide an air hole when using a stove inside the trench.

A-Frame style tarp above a snow trench

The next tarp variant I tried was to pitch the tarp above the trench, A-frame style. This was much more wind resistant and luxuriously spacious inside, but requires one or two poles to form the A-frame, limiting the number of anchors you have available to hold down the tarp, if you’re forced to use gear as improvised anchors. As with the flat tarp pitch, eliminating the open end of the trench is key, but narrowing the trench is less important – and this variant is ideal for two people, given the interior room.

Conclusion

Using snow to build emergency shelters in winter is an important survival skill and well worth practicing if you plan on camping in the backcountry in winter or you’re interested in traveling as light as possible by bringing a tarp instead of a tent. All you really need is a shovel, some snow, and a little know how to get started.

13 comments

Building snow shelters is fun, and I think that it is a really good skill to have. But if going for a trip where I might build a snow shelter (for fun or for emergency) I would not go without a decent shovel.

I've built only three quenzees and one proper snow cave (actually two combined forming enough room for 10 people). A proper big shovel is really helpful when building a quenzee. If there is 30-50cm of snow, it takes about an hour for two to pile up the snow. Then you have to wait couple of hours to let it settle (the colder, the quicker it settles) and then carve it. In best case only the top layer of the snow is hardened and the snow inside is loose and easy to shovel away. It takes less than an hour to carve a quenzee that would sleep three comfortably.

Snow caves require large amount of hard packed snow but they are superb shelters if snow conditions are favorable. With proper technique (no tunnel, full height entrance that is partially sealed with snow blocks when carving is ready) they are really quick to build.

Your neighbors must think you're insane. I love it! I'll second the thoughts on snow shelters, though. I was on a NOLS semester many years ago in Wyoming, and we base camped in quinzees for about a week. Temps outside at night got down to -30 or -35, but it stayed warm enough in the shelters to just wear our base layers most of the time.

I've been thinking about bumping your old snow shelter post with all the snow you got up there this winter.

My brother and I built a quinzee in the yard when we were about 10 so it's not something that requires a lot of technical knowhow; just lots of energy.

Pennsylvania isn't quite hardcore snow country but warmer snow is much more friendly to construction purposes; particularly when it's tacky. I built a 3.5' high windbreak upwind of my campfire last year molding tacky snow like lumps of clay but the downside was the sensation of it radiating cold. Even without the campfire going I could feel the cold from that wall chilling me so a small tarp would have been more appropriate, at least at the +35F temp. I had.

Doing this is a great conversation starter with the neighbors. They all seem to get it when I explain why.

A snow shovel is really needed to build anything more aggressive than scooping out a simple indentation to lie in under a tarp. I have rediscovered my Voile Telepro this winter.

Burying your packs under the quinzee pile is a good idea. This is illustrated in the Igloo book I mention, as well.

We're getting another foot of snow now and I think my next shelter will be a simple narrow trench, with a side shelf dug out beneath an overhang to provide a bivy platform. I am having so much fun! :-)

Yes, on my next test/practice, I'm going to dig a hole in snow about waist height and then try to expand it under the snow crust so that I can get a snow shelf for my bivy bag along the side under the overhang, and maybe a wider area near my head where I can cook under some cover. Dealing with a tarp is a bit of a hassle unless you can cut blocks to anchor it, but the snow conditions have to be perfect and you really need a saw.

I acquired several "butt sled" disks that we use on hikes in the mountains- but it seemed like extra cargo if I'm not going to sled- Just a little weightless fanny disk, but it could double as a shovel in an emergency to build a snow pit for a fire… Hikers are always told to be able to build a fire, but how many have given thought as to how to do that in snow?

Seems to offer better use in a variety of snow conditions, not just deep powder packed snow. Not UL but if it works you don't have to carry as warm a sleeping bag. Trade offs as usual. What do other people thing of this. I must say I am very interested.

A little short on the important details. A well built quinzee will NOT fall in on you.

A few years ago we built one for a group of eight (probably should have made two but we're all good friends). After two nights at -40°C we could not break the roof with five people on top, we had to cut it open with snow knives before we left.

The slab process is similar. You tromp down a large area (snowshoes work great), leave it for a couple of hours to set like the quinzee pile, then carve away. Cutting the slabs vertically means you don't have to try lifting them flat, they stay together better.

I was over at my sisters looking at the big snowpile by her driveway and started thinking; long broomstick, hotdog, her dogs; poke a long horizontal hole into the snowpile and shove a hotdog into it and call over the dogs.

Much time & effort is wasted on hollowing out the center of a Quinzee. This method uses less snow too.

Instead, make a hollow area before you pile snow. Use 6-10 old fiberglass tent poles and a heavy blue or silver tarp to create a dome. Duct-tape the centers of the poles together. Do not let the tarp edges extend too far from the dome. Keeping the tarp tight is the trick — use logs/rocks/ice to roll the tarp inward. To start, a person inside helps. PIle snow >2 feet deep, using sticks to measure depth. Let solidify for 2 hours. Tunnel under dome, remove tent poles, remove tarp, add an airhole, and then create another dome. Use a backpack for a door.

If you’re packing large shovels, might as well take a tarp & poles too.